MRbrew Stainless Steel Carbonation Cap, Ball Lock Keg Post 5/16'' Beer Line Nipple Barb & CO2 Coupling for Soda Drink, PET Bottles Counter Pressure Bottle Filling Cap with Gasket & O-Rings

These do not at all work and I'm surprised nobody has noticed. They went to a new design, not the one shown in the pictures, with a spring and a piston. Not sure what's happening but I think they don't provide enough back force to open the valve in the cap that goes on top. I have tried _3_ of these with this new, non working design that apparently nobody noticed literally doesn't work, and only the old design works.

I got this to replace a plastic carbonation caps that I use. I am a homebrewer, and when I want to take beer over to a friend's house, I can make sure that I keep it with the best quality until it's opened. Additionally, I use these to keep soda carbonated. It's cheaper to buy soda in a 2L, but if you don't drink a lot, it will go flat quickly... but not with these bad boys!

This is a high quality carbonation cap. My ball locks fit it perfectly. I disassembled and reassembled the cap and everything fit well. I filled an empty bottle with co2 and did not lose any pressure in 2 days. This is a lot better than the plastic carbonation caps. The bottle becomes the consumable item instead of the carbonation cap.